SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '760f8e75aba2cd8f20f9ce390e12800bd551fdbfd6ee7f9207e2075b3426ae1f' 
  AND token = 'K0izvg4bA3utqqKPzSOYNmS6gL8jZL+ul3wCJXNj7Zg=' 
  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"
    }
  }
}