SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c73e64b2278d542ab89b82fc1916154123e287f7dbbdc437fae06934273f9f75' 
  AND token = 'bXSc9odNw5EBAGmZcJ4lmL/0M7rdqZ/FhfMhJSYvKYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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