SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3622c23691c0b26ed1a0627c28de1b1ba5aec1932596573190c8745867b9ae4b' 
  AND token = 'yb6FzSSGM8K+41AXCpJODEGzwWs3g0LtTjfRBCZvsBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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