SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e4fe2e670d2343f3c6d061fa0bac17c8cbea47cc3e15b6e512aaeee351008ca0' 
  AND token = 'iQP22Qqa6Fq4Pdc8Qf1nPYluzp67oraKtdZJzoHSVE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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