SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef3c74d5302c7dbccc3903aef636645bc2eeb5fb04a52aafcad12782ba8af020' 
  AND token = 'EIncpNvL7jU3tWolRKOQMEBPkYkQG7Zy2ROH8VEUlmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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