SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae86a0bedb844948fdf5fe70e13b11348db970010754783f84031e22d5d42211' 
  AND token = 'MEmqKsuZ8907u1AnSSpSocAT25yvjetKZ1V4z3pbQbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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