SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e0a33575ff59e17ce54267e0a631e8589f5ef0ca758aca73258efb1812963f5' 
  AND token = 'ryRLTQ6dblEy4liJ0THf+g4AqhVK+YNs76uAr7Waa9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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