SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f23aa748c34be1446c3e727d64554bce074d4c7a0d2d58d37ecbd89c2e1382b' 
  AND token = 'tsq94RwAMu9gfZCCHCfH3nrGsTOhEMpkB58iuohxMI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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