SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '637fac3547690fed9fd7151b2d3f2aec8b9ca202b995adfc69f330dc58297036' 
  AND token = 'nHbt+aCnvMviwo8c4OPbjBaKVO5xcxfLeOW7LFK0ejc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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