SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '832d518b59fd7be43265c1fe2f25d91ce5e1422c494b31c931602aeebc4fa131' 
  AND token = '3Z3mXiatC4+F+uCKCbB9WVQAOcgXEuEigbmHZUmmIQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}