SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb0ec9374fc56c180fc503c211fa4584dfdbb61a5a08abd7acd9c17e348be7b1' 
  AND token = 'RCHHodRIT6YOpev/6aBXF39QonNmauixyHYz2KReMso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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