SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abe9501db762681410c9bef4cdaf6e2f9f4d5db4dd2337109225818896441ebb' 
  AND token = 'SDSbfTovYTZEqmO+kSURJhiTJD9bNQuqisc8qGVPzIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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