SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ce893345dba1dd10cb0e6b9f92f24f8d454e9f2cc3f0d5e3f13062f17679e17a' 
  AND token = 'e55zo/lsze3X4hT0yoOewVmwMcTy7isCs7rmrSydUI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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