SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2bbc32cf1a6abcfa106955750a57cc0523b21923c013ce3c00d241e0d5a272a' 
  AND token = 'X7OIzAuG3ClWM0kE7KsAmHyxPyMfasRBbtH8Ty8e90U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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