SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f03d5888eb4c2d9f645870a52ce94f360d0cb0b87971721072d74e153dc610ad' 
  AND token = 'mH01BYVHpFvlduFyDXb+QlhpArQxsvrbjv3iELaLtOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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