SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4bebde6a0c195205bf157d23e45631d3237f269edf382c430e5649e9e3a0de7' 
  AND token = 'yPIcoreH53LZ4AKQzkWzZG/1OXsWTGW5Hw68FL8tNt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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