SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e31e0d7bc6f7752d52644db358037ca312f0881293882b5c73f41ec0d196225d' 
  AND token = 'FlgKjzmeThK7qX+AXCIqUAJUwVxzLq1LhcGS4AQowAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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