SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f86a6b26681d727a7128e64106020b9a7742d625a46f35ac8aeb03c103a9366' 
  AND token = 'OJcAuEHkBPECH0V0Z/hHDhr/ER7yR5qco77SVdId51M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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