SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc6bfb9dac4c4582fead930e0487aa58e6a7f5e4877f52c5a9472f8f1a67868e' 
  AND token = 'MVZv+BBzyGBdswhCmhhhKEgIQdjIESGY7aXbmU3kAtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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