SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ed20b376efd2d774a99d36864f588981b37688b2bb1e40315ca9d418b08d4219' 
  AND token = 'asrH4qkzA2pLXfCsSTTyIzsZC3HIgPNm4RHzhwe6620=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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