SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f707479330542ffb7da92635ff111c967defcbeb2626a0f84ef505f2c86a5b73' 
  AND token = 'AGOeoarEGF2I/imYapKpTeEnWUcgs+yqSQrmRWcGH8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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