SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70afc1010480606765fb98b5e664ac4ddb68f64252a952760c3cabaa641eb8c9' 
  AND token = 'zTdDaZ7X3HqTUepTfBYa/B9VOrHnqMBARbThDKuCr/M=' 
  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"
    }
  }
}