SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a3347c47d5ea31529e0f02642e88d46230e151961c573cb01399aaf5141b5a01' 
  AND token = '/fHzc8e4NJ+VdSUqY6/k+SEtI2PzGHJVzzlB4ZtL/A4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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