SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a419f8015a2bd299a7591cde3e8938d1ca5a78c0dea23c23ffeb2a91ed03fe7' 
  AND token = 'WK+AMEK2PyvIYYVL4wVMaQmFiA7W0I9eIwzflpBBFS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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