SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9be1d14cdc9f358ab541f85a993f4ae5e30a4bc9692eb9a46d7da2a16c69c994' 
  AND token = 'RsjyjJjOee4kp4WIpyy2/3ZsF7APsc/3BvA/nUaH6Lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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