SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f365757110103ac6fa11788caa6a644e1eb18fb04b093e377e30ed0c4c52ff83' 
  AND token = 'g38vgiW2y2VH+VcnqsYKpqgJo91MPeBILD+K2ykz+kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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