SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '806c65d36939145b539e6563131b4cb046dc27ee80fce0845ba82932bf6e054d' 
  AND token = 'ppEUgq+1OniFmPUL9EhK3oFyzHokIAQYJakWoO8yAD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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