SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '572d831ce0fdba65725b675b3a0caa316175bc3d80ea42c7bb0ddfcf09186987' 
  AND token = 'IGKGOtpGABCGHo0dUXxfo2YhxAJwAHmi5S2xbHwPskA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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