SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4cea7a46d92aececd2764d26e431528bc3940c30170dee1467741e32b6db20f' 
  AND token = 'XIjXLvvX6awDUW+aDhvxpy6qdpQw7xmXtxMPA6hL/1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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