SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5165291b02ef10f79efb1279f6f39b4ae5340fbc81883d652d5bdf51434ca377' 
  AND token = 'V++rydlmrKdd6pkkUfMPqMSKPXZ8GKOu39KFfqAw82k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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