SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb805627406c57c4cfe2a0880a8dfc2d555b9dbd8ac6abdd20aa4b722415cee0' 
  AND token = 'D+zqQj9zopw7wJYDXFP6yYP10jnwFYf0xUPsyGcGm7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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