SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '03536285058a1d095f3bb9c5bc0f497330f5c1e26ce042920db436421c20f580' 
  AND token = 'aST24VnGceTPfm4eknbviiwViViQNxVIHZtwp13Whzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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