SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f3211edd8969f3be90a5ffb88f16f1a542882677aa8dc62ffef42be31dd1f4f' 
  AND token = 'XbKPRMfKI5Y4RfVekMdmvXvwJHIcrUAHU/N+/xcE/NQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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