SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b95647e25b9b18302196fa42c41132605e29ddcf55157bef28a46b7ba50d18d7' 
  AND token = 'IffYTEsHjIjjNFOMuPcCxE4WVp635MNgmUZ1uZKaarQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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