SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b539ee2f2f44c06ae86cd47550a083fc5f76731f4f418ccba02642f7563541' 
  AND token = 'tIo1A2TWm8o0hWqwnoPdeqhIJu4FO/KkxrlMw1xK1v0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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