SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dbe213e135676e5926ee2d15d61e17c3302bff6cf714f7a3ee224ba4d78d749' 
  AND token = 'lJaCkkSorRyQzjMHlfw3LnnGlBAcI4/aNoTSZ4f/ti4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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