SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e69d7c78002efc36cb8da9cf6073c9235d02892dec6f2bbe48047587adbbe7cc' 
  AND token = 'NX5tnxWx45ZMY2S4KtYN9iOmWMa6PdPgylqOOvxtaYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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