SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3e114c09d169b67b95e45c17397985c5e816a8413284db6cadd5640ae9c593c' 
  AND token = 'djV6hrISiPtFrl3kEaK/P7lDKxJHJiC1zftugoP2BoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}