SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '66e8b732dfa16f22f097954fc602620e7aa8150ca339a2ce43add51ee26ff5f3' 
  AND token = 'XAC/RMGHEWwk8rDDqzBnnF6tbKYaGKPsVEeVvUIS2fE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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