SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '590af6d85e20889a96e75559494212ede1345dd8a7d85c35d4b468f4eec77814' 
  AND token = 'DMr/SpbwVHAHHZADFFwORlCsSP4XvGG/t6YHJWRkjAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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