SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a909a9560e7d3f9389653f455cc0e30eb6a6d3770ffe8335927778fdb88c81a8' 
  AND token = '9x7BNLVz0EjHLLLFs2Depu6wKJ9UPGtT2HsHUCSC+uo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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