SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5700f7a6aabf9757a3e92049f1f61ff2bc8ee838bb3b6fd17434eb892a99ff18' 
  AND token = '9LuKSCN0ff90AFkm5yjXYJ2w2hTG7CXE3SYKqerEOvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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