SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de5b97a3dd0cf5671129c8313b1f232c7e29b9522143a402fbb09141751876d3' 
  AND token = 'GEivLIWeoerQZuMT/++5ba5OOC+X6y9pN80iUY950yg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}