SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '451fd5d5afd4c1f4e8cab63166be281981eb7cfc2159276a8f44d702138d2619' 
  AND token = '5sjFZ0z1XWV6vwJgMTjBEqaxL169Dvud81OFJ8zCO/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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