SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90bff9c426a18b1a19218ccd7f28db93033a4e49c6a2354fc10186fe94aa43d1' 
  AND token = 'jd1A0e4rY/ZDXXmDtY5NeeJCaKiFfFL2SCFjZu0eSxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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