SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37ea9d26571867b1325c6cca62637fb5d16fbfef07cc06f751835fdae27dfb12' 
  AND token = 'BPcrrWgHjdIG+1l4rpJQTWWgNa3QO8wGFyqeYeya+zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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