SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3868560a2b76c5504a26c90e64bf2cefada1bcb14b34c073a4c2e4678f4f62ce' 
  AND token = 'LsjdC7OlgShlwhEgLxOUk+irOsIRE8Q8RTcAfYr1Mug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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