SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4379840f71e35492ba794aa2ad3525cc2bdd5ad73844b4d58cdf3c08291d4bbb' 
  AND token = 'zAZdp2jwpJEh84g6yUUF7Eb6QgVztv+EPYBCcxplhP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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