SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80d0322b75d33a275818abc2e05635f37971ff9635533543d80a4c1f5804a0e3' 
  AND token = 'HOwEUEkcKwkex7niGHZOIbqqZoRWLAeI/sLG5LB3+Ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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