SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1d719b169238cc2178a77f19c04d67bb5b29de842cf9f91f7f2995c27a73cab' 
  AND token = 'g6pzr/Z/pm8BZQ0m9PqsY8x1l01yIheNCMHFQkn9Mfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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