SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1fbce66ae9ed7ba1003491f34ffaf33f45296ffd770186ad528a4c38ddacaff' 
  AND token = 'i/AHs0pL8vDuDtR5yx5Ep0Aa0UB+j1Bb1RxesDilrGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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