SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d6df49432ba760a59890288eba7fb22afa0a1c787164269dc9418ae1ab3a0aa' 
  AND token = 'cI/7QfodMaf1BhhIVRFdEP8tFg5LUmzlM9PjpLstGbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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