SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '506417bc8a6af47eb5682d5b896dbbd074da1f22a34a20a8463b96af3be849ce' 
  AND token = 'i9JntRSj7y4zAhpysKa7sf7G8P2dvX1UggAfqsfVgXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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