SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e628b0b91231d6575e1f8fe88e990362b18525423b68fd34c4ff1b09da43044' 
  AND token = 'GbCh9uMxRI8SdyWzbkHluOyFVhyWsJVXJdjyG/pEMME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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