SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3f69e092edf19c1f6b9d033966281a466ff2fc71784bdcf11483366c846e7c' 
  AND token = 'Ffq86TcnU2MVlciGvmqc4J2wzqjl8j/CEPF+c09BW9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00101

JSON explain

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