SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86cc11183f527aa115491e127fda3534341b771b2fa1513868b601b79d7b2965' 
  AND token = 'Xw+X7vRwkdlMrqc1pj2muhpIVb3B57xWVg4nV2HyavI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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