SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d80fc3fda8d50f7699d5f7e9c73b25287ccda3ac7012dfbc1f1d926f53f3f2' 
  AND token = 'nx/oVmVaoFrUpF9A1wCFPGPjSIjQItmfZS3FKCXcB5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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