SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba3832a2cb1cf836841a62f1e45f4b067e7ad99f0645bf9d231d70e84e3b0fb0' 
  AND token = 'Khc/s5WnLtiakiBKRNODED64eTST/xVILSA8ytaDUBc=' 
  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"
    }
  }
}