SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea8dbb435696092ccd67c3539c0931e8074cae5a91ecb7d34b8b80415c9116ba' 
  AND token = '1n17CBUY8swrq11wxhHF/0/sPICQLFTfIYUxODGhBT4=' 
  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"
    }
  }
}