SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '04f42fb31c85323da61a2a6e3388dab2642057253ad7646e5a45f814b8123733' 
  AND token = 'sk5GOTYrMxE2A6IdkYqlNAKIdxf6CZd+4DIvTJLUGgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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