SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '18bdc2e02095a35031d511bf5ca2136c674f74e0e9de12865dd69af8aa22160f' 
  AND token = 'lhVF4FHZMnFTirREDIKUDtGpsF71C+SR1K7bmi1MtXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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