SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8e55ac2039760ab6d0a57e445f3e0e4b90d960c087620b3d675312c1d3099c1' 
  AND token = 'jWNooFQPUuZo9fehvaxRcNSHu3A/3HQvjhlTdiJ80wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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