SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a851aea76cf5c4e0d32f34096335ee411bd4495a82bd3ba04e9958776fc70f80' 
  AND token = 'Ruby1jS50LAfIBOeeaPDOmiIRLVNbq1XinpYhIIkmzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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