SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6b1615f80a3c762de2995270845b72f0feafb07c74cbf4ef209287f250d87cf' 
  AND token = 'LHUtfa5rco9nYKCvXIsPmvWLDppj0mtb2vPsmQerkUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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