SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e699412bf37b9c71e13daba8439eca7cfb8f2168582adfdc3057f6be63dc979c' 
  AND token = 'A6zy19CTM8BMoPs8mGPns1sqoh8A5gjUWFJRuQv5rVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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