SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa65ce94fbaf36eff6392d0301735132004270361617f0cd8085bbfaf6ae9fc3' 
  AND token = '83ElYROyFzoKRwu9cvUPKIKM6Lirr++l2VT8keuLkI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}