SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4088f750b3d65a0e6ddfd43a5faf4483f8cbb3e08faed405d27d24d1a624c5e9' 
  AND token = 'v8+OeOKmk3FODqW0KteH7Bbo71qYFIPjLSGy5OS2DN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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