SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab8a64606adba6be67b1321c16e4a465f3f0d3f6eb07115fc3c18367476fcfec' 
  AND token = 'JwP31OxjK9Bimm3VjmWZnNzouH6LjtjbBdB5EQlqpCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}