SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f28cbbc9f92a0b82aabea4cbb9aac97714c27f785ac74d986e036a8ca1305e75' 
  AND token = 'jWmo9hI/iCtidesYBYihfcliIM/G4J6kMFkgLXpofls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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